Pipe sealing device



NVENTORS Aug. 30, 1960 E. K. FERGUSON, JR., ETAL 2,950,702

PIPE SEALING DEVICE Filed May 23, 1955 2 Sheets-Sheet 1 /.FERGUS0N,JR

mvo/:3.14. KRoNr/ILL ER lli Aug. 30, 1960 E. K. FERGUSON, JR., ETAL2,950,702

PIPE SEALING DEVICE Filed May 23, 1955 2 Sheets-Sheet 2 :NVENTGRS E. K.FSRG usongdr.

2,950,702 Patented Aug. Zzlll9 1950 ene sername nevica Eli K. Ferguson,Jr., 16127 Via Tomar, San Lorenzo, and Bill A. Kre Mliller, 1642Moreland Drive, Alameda, Calif.

Filed Pvlay 23, 1955, Ser. No. 510,092

3 Claims. (Cl. 118-408) The invention relates to a method and means forsealing an installed subterranean pipeline carrying an aqueous liquidand subject to lateral leakage through it.

As is well known, installed pipelines for carrying water or water-bornematerials, and formed of pipe sections connected at bell or similarjoints for allowing iiexibility in aligning and laying the pipe, usuallybecome subject to more or less leakage at their joints subsequent totheir installation. lso, such pipelines may have or acquire points ofleakage or seepage at other portions than at their section points byreason of porosity or spot deterioration or the formation of crackstherein. Accordingly, it is frequently necessary to subsequently sealsuch pipelines against exltration or intiltration at the joints andelsewhere, and it is a present general obgect to provide and apply aparticularly efficient pipe-sealing composition in such a pipeline.

Another object is to provide a particularly effective method forapplying the pipe-sealing material progressively along a pipe bore at acontrolled rate for insuring a most eicient application of the sealingmaterial at leakage or seepage points of an installed pipe.

A further object is to provide a particularly simple and effectiveapparatus for carrying out a pipe-sealing operation of the characterdescribed.

A more specific object is to provide means for effecting a sealingapplication in a pipeline of llocs of a hydrous metallic silicateselected from the mineral group consisting of saponite and bentonite.

An added object is to provide a pipeline sealing treatment whichprogresses in successive stages to finally provide a highly etlicientand generally complete and permanent sealing of the pipeline.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth or be apparent in thefollowing description of typical embodiments thereof, and in theaccompanying drawings, in which,

Figure 1 is a longitudinal and fragmentary sectional view of asubterranean pipeline comprising sections connecting standpipes whichprovide manholes in the line and having apparatus of the present sealingdevice operatively installed with respect to the pipeline.

Figure 2 is an enlarged fragmentary View showing a sealing arrangementutilizing a movable pressure-controlled partitioning element in apipeline section.

Figure 3 is a section at the scale of Figure 2 showing an alternativelyusable apparatus relatively for high-pressure and progressive sealing ofa pipe section by means of a moving head utilizing relatively smallquantities of sealing materials.

Figure 4 is an enlarged partly sectional edge view of a bore-closingplug of the apparatus.

Figure 5 is a partly sectional view taken at the broken line 5-5 inFigure 4.

Figure 6 is a partly sectional view of the pipe-partitioning unitelement of Figure 2.

As particularly illustrated, the features of our invention are shown asapplied in the sealing of a subterranean pipeline L disposed below aground-water level W and having successive pipe sections P connected atsuitable joints thereof, with portions of the line connecting relativelylarge standpipes S of suitable structure providing manholes M at theirtops. The pipeline L may carry various aqueous liquids such as naturalWater for `domestic or irrigation use, water-borne sewage, or drainagewater, it being noted that the particular aqueous liquid to be carriedby the pipeline L is generally immaterial with respect to the nalsealing of the pipeline by the present methods and means. Also, it willbe understood that the standpipes S essentially provide anti-surge oroveriiow passages in the line, with manhole covers normally requiredonly where the pipeline extends beneath utilized ground surfaceportions, as a roadway. The present pipe sections have bell and spigotportions Q and R at their opposite ends and each line joint so providedis primarily sealed by a suitable packing T which is compacted withinthe bell Q against the exterior of the received spigot R of the nextpipe section.

In pipe lines of the present character, the standpipes S are usually ofconcrete structure, while the pipe sections P may be of concrete orceramic or metallic compositions, and it will be understood that suchpipe line elements are generally subject to leakage at their joints andelsewhere in a direction determined by an excess of hydraulic pressurewithin or about the line. Even though such pipe lines are usuallysubstantially leakproof when originally installed, deterioration withage and/0r cracking and/or the penetration of plant roots may result ina serious aggregate line leakage which it is the primary purpose of thepresent sealing ldevice to eliminate or at least reduce to a minimum.Accordingly, and as particularly illustrated, the sealing device of ourinvention is shown as applied to an installed pipeline which issubmerged in ground water extending from the level of the waterline Wwhich is intermediate the pipes of the line and the top of the ground.Referring particularly to the showing of Figure l, it will be noted thatthe installed pipeline L slopes downwardly to the right whereby agravity liquid ilow through the pipeline will also be toward the rightof the view. The present pipeline L includes successive runs of pipesections P connecting a succession of standpipes S-A and S-B and S-C andS-D which extend upwardly to or beyond the ground surface thereat.

'It will now be noted that a sealing of the pipe line is arranged to beeffected from the interior thereof by providing water-borne ocs of ametallic silicate Within the pipeline for their flow with escaping waterinto leakage passages of the pipeline until they have sealed saidpassages. More specifically, the mineral saponite comprising a hydrousmagnesium-aluminum silicate is a preferred source of the silica gel ofthe sealing ocs. The use of saponite as a source of the sealing flocs ispreferred by reason of the superior behavior of water-borne saponite inthe presence of certain llocculating and setting materials which arehereinafter discussed; it is to be noted, however, that the mineralbentonite is usable for the present purpose, though its flocculatingproperties in water suspension thereof are not as complete or pronouncedas with saponite. Also, for assuring a complete sealing of a pipelineunder treatment, the sealing medium may usually be most advantageouslyapplied within a pipeline in successive stages of preliminary silicasealing and silica concentrating and silica setting by the successiveapplication of certain compositions which cumulatively provide the iinalseal, and are hereinafter, for ready reference, designated asCompositions A and B and C.

As is particularly illustrated, the apparatus for carrying out certainline-sealing steps by use of the various Compositions A and VB and C isshown as installed in connection with line sections, or pipe-runs, L-1and -L-Z and L-3 which connect successivestandpipes of the pipeline L.VThe elements of said apparatus include sealing plugs 10 for removablyfitting the ends of the line sections, valves 18 for possible use withthe Vplugs iii, a spherical partition v20 movable along a pipelinesection under pressure control and a compartmented partitioning head 30Vwhich is progressively movable in alsaid line section. Y

With particular reference to the various compositions used in carryingout our process, said compositions are identified essentially asfollows: Y

Composition A A .water-suspension Vor slurry of saponite comprising 1.5%to 4.0% by dry-weight of saponite; this corresponds to a slurry strengthof approximately 3.0% to 8.0% of the commercially available pulverizedmineralV saponite.

Composition B A' mixture consisting of 50% by volume of Composition Aand 50% by volumerof an aqueous sodium silicate solutionrhaving'a ratioof alkali to silica of l/3.22, with a gravity of 41 Baume and aviscosity in poises of the aqueous sodium silicate solution ofapproximately 1.8. Y

Composition C.-A solution containing 5% to 7% of sodium bicarbonate byweight, or other salts or acids which are acidic tolthe sodium silicatesolution of Com-V position B, such as calcium chloride, sodiumbisulphate,

sulphuric acid, etc., and selected upon the basis of theY reaction Vtimeavailable and the quality or type of nal silica gel desired. f

By particular reference to Figures l and 2 and 4 and 5, it will be notedthat a sealing plug 10 essentially comprises a disc 11 provided with acontinuous axial edge flange 12 which functions as a rim to mount aninflatable hollow tire-like sealing ring 13. The sealing ring 13encloses a continuous inner tube 14 from'which a valvestem 13' providinga normally closed check valve extends through the rim 12 of the disc foruse in inflating the ring with air; the size of the deflated ring '13 isslightly less than the bore of pipe sections to be engaged by it,whereby the inflation of the ring will sealedly and axially fix itwithin said pipe bore. A relatively short and terminally-threaded pipenipple 16 extends axially through the plug disc 11 in sealed relationthereto and is arranged to sealedly mount a cap 117 or a shut-0E valve1S on either end thereof. The sealing plugs 10 are arranged for fixedinstallation in the ends of the installed pipeline sections connectingadjacent standpipes S, and are so positioned in the section endsreceiving them that the ination valve-stem 13 is accessible from theadjacent standpipe spaces.

The structure of a movable partition 20 is brought out in Figures 2 and6, and this elementpcomprises an inflatable hollow sphere or ball 2.1 ofrubber or the like provided with a normally closed air-input check valve22 v of a usual structure'atra side point thereof, with the valvestructure extending solely inwardly from the exterior surface of thesphere. The valve -22 is arranged to provide for a maintained inflationofthe ball to suchk a sizeVK thereof that it may under certain pressureconditions roll through a pipeline section while sealedly engaging thesection bore to function as a moving partition therein.

By particular reference to Figures l and 2, it will now be noted thatthe line section L-'1 and the standpipe S-B are shown therein as blockedoif orisolated from the rest of theY line by means of the operativeapplication of plugs 101at the end of the line section L-'1 at thestandpipe S-A and at th'eend of the adjacent pipe section L-2 whereitenters the standpipe SB,said plugs havingtheir nipples 16 closedattheir exposed ends by caps `17. The pipeline portion thus blocked offis preferably filled with the aqueous mud or slurry of the Composition Aup to a level in the associated standpipe which is preferably at leastve feet above the ground-water level W, or above the pipeline level ifthe pipeline is not submerged in ground water, whereby to preferablyprovide a positive working pressure head of at least tive feet in thesection and so prevent an inflowofthe ground water at leakage points ofthe line section under treatment. The slurry charge so placed is allowedto stand for at least four hours or until its working level in thestandpipe remains eiectively constant as indicating that leakage fromthat pipe section has substantially or completely ceased by reason of apreliminary lilling of any leakage passages and the adjacent back-fillwith the sealing flocs from the slurry.

In case a particular standpipe S does not extend for the required heightabove the ground-water line N, or the unsubmerged pipeline thereat, toprovide the desired livefoot minimum pressure head for the treating,liquid in a particular pipe section, the added pressure head may beprovided by temporarily and sealedly mounting an extension collar (notshown) on the standpipe at its manhole for permitting a building up ofthe required pressure head of the treating composition in the standpipeand pipe section. Alternatively, a sealing pluglt) may be sealedlyengaged in the upper end of the pipe section under treatment and have avalve 18 mounted on its nipple end extended into the standpipe, saidvalve connecting a hose 19 with the opened valve for supplying the iuidtreating composition at any required rate and pressure in the pipesection; this arrangement is indicated in Figure l'l for the pipesection L-2.

When the apparent sealing utility of the depositedV Composition A chargehas substantially ceased in the line portion L-1, as indicated by itsmaintained level in the standpipe S-B due to a lowering of the seepagerate, the remainder of this slurry charge is removed from the pipelinein a manner which does not ush the deposited ocs from the seepageopenings of the pipeline in which they are lodged. In order to insure acleaning out of the Composition A charge from within the line portionL-l, the nipple 16 at a lower end of the section is uncapped totemporarily lower the level of the remaining charge to that of thepipeline, and a removable partition ball 20 is then operatively insertedbehind the remaining portion of the charge in the pipe; in this manner,the introduction of a substitute liquid in the blocked-oif-standpipe inthe line'section may cause the ball 20 to push out the earlieri appliedliquid ahead of it under the pressure of the sublthrough the nipple ofthe plug :10. To avoid the chance of a failure of the action of the ball20 as a valve with respect to a plug nipple 16, the cap `117 ispreferablyreplaced on the nipple L16 before the pressure head of asucceeding liquid charge has been built up, this being the conditionindicated in Figure 17in which the ballr20V engages the opposed nippleend as having been used to clear the pipe section of its priornon-sealing liquid contents as the sealing treatment of the section wasstarted by lling the section with theV Composition A behind the ball 20.Y p

Upon the removal of the Composition A charge from the line section L-1,a charge of the Composition B slurry is introduced into this blocked-offline portion to build up the same hydrostatic pressure as was usedkforthe first slurry of Composition A in the section, and this new charge isallowed to stand for from one to four hours forA adding to the previoussealing deposits. of saponite flocs to thicken and stitfen the depositsby reason of the added flocculating action of the sodium silicatetherein on the saponite in the CompositionrBV and on the flocspreviously deposited from the Composition A. Asubsequent similarreplacement of the used Composition B by a charge of the Composition Csolution may generally be effected by a repeated use of the ball in thesame manner as during the introduction of the charge of Composition B tothe line section L-l, after which the hydrostatic pressure of thereplacing charge is` preferably increased over that used for the twofirst steps by adding to the effective head of the liquid in thestandpipe S-B to insure a forcing of the setting chemical of thecomposition into the positionedV seal, as by utilizing a valve 18 andpressure hose 19 at a plug 10 installed at the upper end of the linesection under treatment in the arrangement shown for the section L-Z,which may be assumed to have been subjected to the first two describedtreating stages with the Compositions A and B, or to have all of itstreating stages effected by its use of the ball 20 and the valve 18 andhose 19 in the' described manner.

Considering the previously described method and means used for sealingthe pipe section L-l, it will be understood that the different stagesmight generally be simultaneously carried on in a disclosed manner in asuccession of three alternate blocked-o sections, with the sealing stepsprogressive in the same direction along the pipeline. Also, in case theleakage rate is originally small enough at a given section beforetreatment, the Composition A treatment may be omitted therefor. Thetreatment in two or three stages is understood to be generally such thatit may be completed in a progressive manner along the pipe line forminimizing the required movement and spread of the apparatus used. Also,the portion of any of the compositions used in the present pipe-sealingprocess which has not escaped by seepage from the line may be salvagedand prepared for its reuse by bringing it back to its best initialstrength by adding an appropriate amount of the seal-providingingredients or water to it as required, this being particularly valuablein the case of the Compositions B and C in which the chemicalingredients are relatively expens1ve.

By particular reference to Figures l and 3, it will be now noted thatthe movable head provides chambers 31 and 32 between axially aligned andiixedly spaced discs 33 and 34 and 35 which are provided with similarlydirected one-way resilient sealing rings on and opposite theirpcripheries, whereby the discs are independently sealed for a one-waymovement in the bore of the pipe run or section engaged by the head. Aspreader rod 37 axially connects the discs 33 and 34 and 3S in xedrelation thereto and is provided with a terminal eye 38 beyond the disc33 for its engagement by a pull cable 39. A flexible hose 41 extends toa coupling 42 Yprovided at the outer end of a pipe 43 sealedly engagedthrough the disc and extending into the chamber 32, and a exible hose 44extends to a coupling 45 provided by a pipe 46 extending through thediscs 34 and 35 into the chamber 31.

A head 30 is shown as installed in the line section L-3, and the pullcable 39 extends from the eye 38 of the head 30 into the space of thestandpipe S-D, upwardly about a pulley 47 temporarily xed in the bottomof the standpipe space by a supporting and positioning jack-bar 42, andthence about the dmm of a windlass 49 suitably supported over themanhole of the standpipe; the arrangement is such that a turning of thecrank handle 49 of the windlass 49 may progressively pull the headthrough the line section L-3, while pulling the hoses 41 and 44 fromabout hose reels 51 and 54 respectively and to which waterbornematerials of the appropriate sealing compositions are arranged to beprovided at connections 52 and 55 respectively, said hose reels beingdisposed on the ground surface adjacent the standpipe S-C.

In the use of the head 30, the advance chamber 311 is continuouslysupplied with a Composition B and the chamber 32 is continuouslysupplied with a, Composition` C, both at a maintained pressure at leastas great as that provided by a five-foot head of water over. theexterior pressure at the pipeline section receiving the head., The headis advanced at such. a rate that the floc sealing from the Composition Bis complete at a leakage point before the Composition C is operative atthat point to set the tloc deposit before the head has progressed beyondthat. point. In practice, it has generally been found that an.-advantageous rate of advancement of the head is between 1 to 4 feet perminute depending on theetfective porosity of the treated pipe portion,whereby the use. of a hand-operated windlass 49 may be preferable to. a.power-operated windlass for pulling the cable 39.

The working pressures in the chambers may be4 variously ascertained andmaintained in terms of the seepage rate from the chambers 31 and 32 ofthe. moving head in any suitable manner, it being understood that thepresent apparatus is particularly useful for usewith. shallow or surfacepipelines lacking standpipes in which the required static pressures maybe maintained. A fu-rther advantage of the use of the head 30 lies inthe fact that less sealing material is in use as compared with themethod using the standpipes for building up the required pressure head.If a pipeline section has a moderate leakage rate, the use of a head 30therein is usually found sulicient to provide the needed seal;otherwise, the treated section would advantageously be treated inaccordance with the iirst stage of gravity pressure treatment with theComposition A of the first described sealing process. When a fulltraverse of a head 30 through a line section has been completed, thesection is flushed with clean water to `remove any ocs of the sealingmaterial from the pipe bore, this procedure also following anapplication of the Composition C by the previously described methods.

In the application of the sealing Compositions B and C, with or withoutthe Composition A, by any of the hereinbefore described methods orcombinations of methods, it has been found in practice that leakageelimination runs from about to 98% of the initial leakage rate ascomprising a most satisfactory result for practical purposes. It is tobe particularly understood that the present pipeline sealing processprovides a plug of a relatively tough and insoluble gel-like silicamaterial with considerable plasticity in a leak opening of a pipe jointor break and in the adjacent earth. Also, a present sealing gel retainsits sealing qualities in the presence of Water, whereby the sealprovided is particularly valuable for pipelines carrying aqueousliquids. And it is to be further noted that a sealing plug provided at apipe leak opening in the described manner is usually more or less beadedat its outer end and is thereby keyed in place against its inwardpressure dislodgment in case the pressure about the pipeline exceedsthat within it, as is a usual condition with sewage and drainage lines,for instance.

From the foregoing description, taken in connection with theaccompanying drawings, the advantages of the present pipeline sealingdevice may be readily understood by those skilled in the art to whichthe invention appertains. While we have described forms of our inventionwhich we now consider to comprise preferred embodiments thereof, wedesire to have it understood that the showings are primarilyillustrative, and that such changes and developments may be made, whendesired, as fall within the scope of the following claims.

We claim:

1. In a device for sealing leakage openings in a pipeline portion ofuniform bore, xed and movable partitions sealedly engaging the bore toclose off between them a pipeline portion for enclosing a charge of anaqueous slurry comprising a water-occulated clay, said fixed partitioncomprising a disc having a pneumatically inflatable rim releasablyengaging the bore while sealed- 7 Y i ly xing the partition in the boreand having arnormally closed flow passage therethrough, and meansforrmoving said movable `partition toward the 'fixed Ypartition forYcreating and maintaining in` said occulated clay chargeV a constantpositive pressure exceeding the external pressure against Said pipelineportion for effecting the pressure'escapefof thercharge into saidopenings for a retention of the escaping ocs of clay as Va sealing meansin said openings. Y n

2. A structure in Yaccordance with claim 1 having means at a discsidefor use in inating said rim and means Vat the same disc side forOpening said ow passage thereatz Y 3. A structure in accordance withclaim` 1 in Which the movable partition comprises -a pneumaticallyinated ball sealedly engaging the pipeline bore and arranged for itsmovement toward the `fixed partition by uid pressure applied behind itand to a limiting position in which it closesV the opened flow passage.

References Cited in the file of this patentV UNITED STATES PATENTS?` f.Y Boyle V Dec Y29, 1908 OTHER REFERENCES Y Volclay: Data No'. 23(7)-31,preliminary Report of October 1937. Data No. 202-M1 and 2,' data No.226, pages 1 and 2, Data No. 232, page 2. Y

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